A new survey from Public Policy Polling (PPP) finds incumbent Democrat Michael Bennet ahead of GOP hopefuls Jane Norton and Ken Buck for the first time. Bennet leads Norton 44%-41%, and has a 46%-41% lead over Ken Buck.

The last PPP poll, conducted in March, in Colorado showed a dead heat between Norton and Bennet.

The poll, which surveyed 1,060 Colorado voters from May 14 to 16 and has a 3% margin for error, found that Bennet's biggest gain came among independent voters. Independents favored Norton 44%-35% in March. They now support Bennet 42%-40%.